The present invention relates to absorbent articles such diapers, training pants and incontinence pads. More particularly, the present invention relates to disposable absorbent articles having improved fasteners for joining the front of the article to the rear of the article and/or to provide for disposal.
Many different types of refastenable fastening devices are known, including ties, pins, hook and loop systems, hook and eye systems, buttons, snaps, interlocking shapes, buckles, adhesive tapes, cohesive surfaces, and zippers and other slide connectors. Such fasteners have been used on a variety of products, both durable and disposable. Typical uses include envelopes, clothing, diapers, packages, footwear, construction closures, general attachment needs and feminine hygiene products.
Some fastening devices, such as hook and loop or adhesive tapes, require aligning an engaging surface with a landing surface. While this can result in an effective closure, it often results in misapplication and/or poor alignment of the elements being connected. Further, hook and loop fasteners can become ineffective due to compression and contamination or can harm surrounding materials. With an adhesive system, improperly fastening the device may render the entire product unusable. For example, in diaper applications, repositioning a tape tab which has been fastened improperly may result in tearing the outer cover of the diaper. Further, adhesive systems are prone to contamination-induced performance problems. In order to help prevent such problems, the use of these types of fasteners often require inefficient designs and extra material usage which can add to the cost of the products.
Other systems such as buttons, snaps, hooks and eyes, and ties are limited in that they connect discrete points only. If only one fastening device is used for a particular closure, the connection allows material around the fastener to rotate around the discrete points connected by the fastener. Further, if a span other than a single point needs to be connected, these systems generally require more than one fastening device per closure. Multiple connections can be cumbersome and can result in gapping between the discrete fastening device components, particularly if the connection is under stress. These systems also require precise alignment of the components to create the connection desired. Some point to point fastening systems require that forces be maintained on the system throughout the time the fastener is connected.
Other examples of interlocking closures can be found in U.S. Pat. No. 198,097 issued to Fries on Dec. 11, 1877, U.S. Pat. No. 207,253 issued to Chipley on Aug. 20, 1878, U.S. Pat. No. 378,874 issued to Davis on Mar. 6, 1888, U.S. Pat. No. 771,719 issued to Copeland on Oct. 4, 1904, U.S. Pat. No. 791,654 issued to Searle on Jun. 6, 1905, U.S. Pat. No. 2,837,096 issued to Leveillee on Jun. 3, 1958, U.S. Pat. No. 3,482,289 issued to Stradella on Dec. 9, 1969, U.S. Pat. No. 3,620,180 issued to Waldes on Nov. 16, 1971, U.S. Pat. No. 3,834,824 issued to Jahn on Sep. 10, 1974, and U.S. Pat. No. 4,001,924 issued to Bengtsson on Jan. 11, 1977. All of these fasteners can join lengths or spans, but each suffers from at least one important disadvantage, especially for use with disposable products like diapers. Some require the user to press on the connection to create engagement. Others require intricate manipulation to engage, such as tucking a tab over one element then below another. Yet others require at least one element to deform to create engagement which may limit the load bearing capability of the fastener. Most lack provisions for allowing the fastener to conform to different shaped surfaces while in use and many of the systems have no provisions allowing for adjustable fit. Further, if used in disposable absorbent products such as diapers, these fasteners can cause skin marking and discomfort for the wearer.
Thus, it would be advantageous to provide an improved fastening device. Further, it would be advantageous to provide a refastenable fastening device which allows easy connection of lengths or spans, rather than discrete points. It would also be advantageous to provide a refastenable fastening device which allows adjustability and which is suitable for many uses, including disposable products, absorbent articles, and especially disposable absorbent articles. To this end, it would be desirable to provide a fastening device which readily conforms to different shapes when in use and/or which minimizes skin marking when used on a product to be worn close to the skin. Further, it would be advantageous to provide an absorbent article having a fastening device which can easily be engaged in many different configurations, such as when the wearer is sitting, lying down or standing. Accordingly, it is an object of the present invention to provide disposable products which include improved tab and slot fastening devices.
The present invention is directed to an improved fastening device suitable for use with disposable absorbent articles. The fastening device preferably includes a tab member and a slot member. The slot member has an inboard portion, an outboard portion and a slot which may include a slit or a loop. The inboard portion located laterally inboard of the outboard portion and the slot located between the inboard portion and the outboard portion. The tab member has a length, a proximal edge, a distal edge and a lip portion. The tab portion is passed through the slot of the slot member to engage the fastening device. Once passed through the slot, at least the lip portion of the tab member overlaps the outboard portion of the slot member to prevent the tab member from disengaging from the slot member. The present invention is also directed to articles which include the tab and slot fastening device. Some article with which the fastening device is known to be useful include diapers, catamenial pads, bibs, wraps, packages and the like. However, the invention is not limited to such uses, but rather is directed to all other suitable uses of the tab and slot fastening device.
The fastening device of the present invention may provide a solution for any or all of the deficiencies identified with respect to other known fasteners. For example, the tab and slot fastening device of the present invention is strong and simple to use, yet it can be configured to conform to shaped surfaces and to be otherwise skin-friendly. The tab and slot fastening device can be adjusted and refastened without damage to the article or to the fastener. Further, the tab and slot fastening device can evenly join lengths or spans of material without the need for multiple fasteners. And, because the tab and slot fastener has a designated fastening configuration, no extra material is needed to ensure proper fastening of the fastener as in tapes and hook and loop fasteners. Further, especially important for disposable products, such as diapers, is the fact that the tab and slot fastener can form a connection between panels without the need for overlapping the panels. This allows for a reduction in the amount of material in the disposable article, and thus, reduces the overall cost of the article. Accordingly, the tab and slot fastening device of the present invention can be provided with the benefits of conventional fastening systems without many of the disadvantages.